In fan coils the heat exchanger batteries have fluid circulation pipes, the ends of which are connected to manifolds through which the fluid flows and return pipes are connected. Usually the manifolds have a block body with a part fitting to fluid piping, two, three or more branches for connection to the battery pipes and a distribution chamber between the fitting and the branches. Generally, this block body is cylindrical and its geometric axis is oriented transversely to the axes of the fittings and the branches which are substantially parallel to each other.
By its presence and conformation, this chamber is already a cause of turbulence in the fluid and a loss of pressure in the system and contributes to pointlessly increasing the external dimensions of the manifold.
Moreover, due to the shape of, and machining requirements inside the body of this intermediate cylindrical chamber, it is left open at one end and is only closed, with a plug that is generally welded on at the end. This plug represents a critical part of the manifold.
At the same time, inserting and fixing this plug requires additional production work time and costs. Furthermore, if the welding is not homogenous it becomes a source of rejection, because in this case the manifold cannot be used.